IBM researchers claim to have built and operated the world’s smallest working computer circuits, using an approach in which individual molecules move across an atomic surface like toppling dominoes.
The new ‘molecule cascade’ technique enabled the scientists to make working digital-logic elements about 260,000 times smaller than those used in today’s most advanced semiconductor chips.
The circuits were made by creating a precise pattern of carbon monoxide molecules on a copper surface. Moving a single molecule initiates a cascade of molecule motions, just as toppling a single domino can cause a large pattern to fall in sequence.
The scientists then designed and created tiny structures that demonstrated the fundamental digital-logic OR and AND functions, data storage and retrieval, and the ‘wiring’ necessary to connect them into functioning computing circuitry.
The most complex circuit they built – a 12 x 17-nanometer three-input sorter – is so small that 190 billion could fit on top of a standard pencil-top eraser 7mm in diameter.
‘This is a milestone in the quest for nanometer-scale computer circuitry,’ said Andreas Heinrich, a physicist at IBM’s Almaden Research Centre in San Jose, California.
‘The molecule cascade is not only a novel way to do computation, but it is also the first time all of the components necessary for nanoscale computation have been constructed, connected and then made to compute. It is way smaller than any operating circuits made to date.’